In Hamilton, U.S. Pat. No. 3,446,856 which is incorporated by reference there is disclosed a method for the selective ortho-alkylation of phenolic compounds. That method is based on the vapor phase reaction of phenol and a lower alkanol in the presence of a magnesium oxide catalyst. The Winkler et al patent, U.S. Pat. No. 2,448,942 discloses an alkylation process whereby penta-substituted phenols are prepared by alkylation of a phenol with a lower alkyl alcohol in the presence of a metal oxide catalyst.
It has been discovered by the applicant that phenols may be selectively ortho-alkylated with a lower alkane by a vapor phase reaction that is carried out in the presence of a supported nickel oxide catalyst. This process is highly selective to the synthesis of 2,6-xylenol. The process may be carried out at ambient pressure and at temperatures below the temperatures mentioned in the above-mentioned Hamilton patent.
Accordingly, it is a primary object of the present invention to provide an improved method for the selective ortho-alkylation of a phenolic compound which is based on the vapor phase reaction of a phenol and a lower alkane.